/**
 * Copyright (C) <2021>  <chen junwen>
 * <p>
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * <p>
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * <p>
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package io.mycat.plug.loadBalance;


import java.util.List;
import java.util.concurrent.ThreadLocalRandom;

/**
 * 随机算法
 */
public enum BalanceRandom implements LoadBalanceStrategy {
    INSTANCE {
        @Override
        public LoadBalanceElement select(LoadBalanceInfo info, List<LoadBalanceElement> entityList) {
            if (null == entityList || entityList.isEmpty()) {
                return null;
            }
            int size = entityList.size();
            int randomIndex = ThreadLocalRandom.current().nextInt(0, size);
            return entityList.get(randomIndex);
        }
    }
}
